It's like film buff complaining that John Ford was the pinnacle of film making, and then crapping all over modern cinema because no one does it the same way. Whatever influences he had on the genre, he had it because of WHEN he did it, and as part of an industry that doesn't approach the process the same way anymore.
Literature, film, music, video games. ALL industries with their share of icons, all of them dependent on their particular moments in time. Sierra's work in adventure gaming is legendary, but today it's the realm of Indie studios and fan productions, with AAA game makers not wanting to touch the genre. Charlie Parker was a compositional GOD (to say nothing of being patron saint of the saxophone), but musical tastes have changed and today he'd be relegated to a much smaller niche audience.
It's one thing to recognize the impact he had, but something else ENTIRELY to dwell on it and crap on everything that's not it.